Double-barreled syringe with detachable locking mixing tip

ABSTRACT

A double-barreled syringe is provided which includes a mixing tip which is detachable after the tip is locked to the syringe body, so that the tip may be replaced by a locking cap. Locking occurs when a neck extending from the body between two shoulders is inserted into a bore in the tip (or, alternatively, the cap) and the tip is rotated so that two symmetrically opposed tabs attached to the tip are each received within a recess determined by a shoulder and a locking rib attached to the shoulder, and two diametrically opposed detents extending from the neck are each received within a recess in the bore surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a continuation application of Ser. No.09/581,344, filed Jun. 9, 2000, now U.S. Pat. No. 6,394,314, whichclains the benefit of PCT application serial number PCT/US99/23604,filed Oct. 12, 1999; which claims the benefit of Ser. No. 09/170,146,filed Oct. 12, 1998, now U.S. Pat. No. 6,065,645, all having the title“DOUBLE-BARRELED SYRINGE WITH DETACHABLE LOCKING MIXING TIP”, theirdisclosures are hereby incorporated herein by reference.

BACKGROUND OF INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to multiple-barreled devices formixing together and dispensing viscous substances. More particularly,the invention relates to a double-barreled syringe having adouble-barreled plunger of unitary construction for dispensing anadmixture formed when two gels stored in the barrels are simultaneouslydischarged into a mixing tip having a five section static mixingelement. The tip, which interlocks with the syringe body, is detachableand may be replaced by a locking closure cap to prevent leakage when thesyringe is not in use. The locking closure cap preferably has a linerwhich mitigates undesirable leakage during transport and storage.

[0004] 2. Description of the Related Art

[0005] Devices for mixing and dispensing a viscous fluid havingseparately stored constituents wherein a mixing portion is detachablyconnected to a storage portion are known in the art. U.S. Pat. No.5,413,253 to C. Simmen discloses a static mixer for connection to acartridge having at least two chambers containing different materials.The mixer is connected to the cartridge by inserting hollow circularmake prongs and arcuate positioning keys of a center plug withincorresponding female outlets in the cartridge. The plug is rotatablymounted within the collar of a sleeve. The mixer is locked to thecartridge by rotating the collar until opposed tabs on the sleeve engagewith locking arms on the dispensing end of the cartridge.

[0006] U.S. Pat. No. 4,538,920 to G. E. Drake discloses adouble-barreled syringe for mixing and dispensing a two-componentmaterial such as a resin and its hardener. Both a mixing tip and astatic mixing element located within the tip bore are flexiblyrotationally aligned with the syringe body so that the first blade ofthe mixing element is generally perpendicular to the plane of contiguitybetween the two component streams exiting a syringe body outlet. Themixing tip is connected to the body by centering the tip inlet over thebody outlet while aligning the tip so that it can be pushed betweenopposed bayonet locking tabs, each having a prong and a stop surface,and then rotating the tip so that opposed ramps on the tip inlet end arewedged between the prongs, and a stop surface proximate to each rampengages a tab stop surface.

[0007] Although either of these devices enables the storage and mixingportions to be connected and then detached multiple times, both are socomplex as to be unsuitable for mass production of inexpensive,throwaway dispensers. What is needed is a device which on demand canthoroughly mix two-component viscous materials and dispense a desiredamount of the admixture, which will not leak when set aside, and whichcan be mass produced at relatively little cost.

OBJECTS OF THE INVENTION

[0008] Accordingly, it is an object of the present invention to providea simple, reliable and convenient device which simultaneously dispensesequal amounts of two well mixed viscous materials as an admixture.

[0009] Another object of the invention is to provide a device which canbe repetitively used to dispense desired amounts of an admixture.

[0010] A further object of the invention is to provide a device having astorage portion and a mixing-dispensing portion which repetitively canbe easily connected and then detached, wherein the storage portion doesnot leak during storage and transport thereof.

[0011] A still further object of the invention is to provide a devicethat is inexpensive to manufacture.

[0012] Other objects of the invention will become evident when thefollowing description is considered with the accompanying drawingfigures. In the figures and description, numerals indicate the variousfeatures of the invention, like numerals referring to like featuresthroughout both the drawings and the descriptions.

SUMMARY OF INVENTION

[0013] These and other objects are achieved by the present inventionwhich provides a double-barreled syringe wherein one barrel contains ahydrogen peroxide water-based gel formulation used for teeth whitening,and the other contains a gel formulation including compounds that willaccelerate the release of oxygen from the first formulation andconsequently increase the reaction rate of the teeth whitening process.The syringe dispenses an admixture formed when the two formulations aresimultaneously discharged into a mixing tip having a static mixingelement. The tip, which is in locking connection with the syringe body,is replaced by a locking closure cap to prevent leakage when the syringeis not in use.

[0014] The syringe body includes a double-barrel assembly havingjuxtaposed first and second barrels having a common length and agenerally cylindrical bore of a common diameter. Each barrel is boundedat a discharge end by first and second shoulders, respectively, witheach shoulder having a generally planar surface. The surfaces arecoplanar and contiguous. A generally cylindrical neck extends from andis symmetrically disposed between the shoulders. The neck includes firstand second outlet passages. Each barrel at its opposite (plunger) endclosely receives a piston within its bore. An arcuately-shapedfinger-grip circumscribes the contiguous plunger ends of the barrels.

[0015] The syringe body further includes a double-plunger assemblyhaving juxtaposed first and second plungers of a common length. Eachplunger extends at a proximal end in an end-piece rigidly attached toone of the pistons, and is rigidly attached at a distal end to athumb-rest common to the plungers.

[0016] Alternatively, each plunger has a seal formed integrallytherewith at a distal end thereof The seal preferably comprises a flarehaving a wall thickness which is sufficiently thin as to flexiblyconform to the bore within which it is contained and thus seal theplunger upon which it is formed with respect to the bore.

[0017] Further, according to the preferred embodiment of the presentinvention an alignment ring is formed proximate the distal end of eachplunger. The alignment ring is formed proximal of the seal. Thealignment ring enhances alignment of the seal with respect to the barrelwithin which the seal is disposed. The alignment ring is coupledcomparatively flexibly to the shaft of the plunger and the alignmentring is coupled comparatively rigidly to the seal, so as to allow thecombination of the alignment ring and the seal to move together as aunit with respect to the shaft while also causing the alignment ring andthe seal to remain comparatively fixed in position with respect to oneanother. In this manner, the alignment ring and the seal remain alignedwith respect to the bore within which they are disposed regardless ofbending of the shaft of the plunger which may occur during use.

[0018] According to the preferred embodiment of the present invention,the alignment ring is attached to the shaft by a first neck and the sealis attached to the alignment ring by a second neck. The first neck has asmaller diameter than the second neck so as to facilitate movement ofthe combination of the alignment ring and the seal relative to theshaft, while maintaining desired relative alignment of the alignmentring with respect to the seal. Thus, the combination of the alignmentring and the seal tends to move as a unit with respect to the shaft(which may bend independently of the alignment ring and the seal).

[0019] The syringe body further includes a first mating assembly havingdiametrically opposed first and second detents extending outwardly fromthe neck, and opposed first and second locking ribs symmetricallydisposed with respect to the neck and rigidly attached, respectively, tothe first and second shoulders. Each rib has a plurality of generallyplanar locking faces generally parallel to and at a common predetermineddistance from the neighboring shoulder surface.

[0020] The syringe further includes a generally conical mixing tiphaving an inlet end and a discharge end and a bore therethrough. Thebore has a generally cylindrical portion at the inlet end and extends ina conically tapered portion toward the discharge end. The cylindricalbore portion is determined by a circumferential surface adapted toclosely receive the body neck. A four section static mixing element isclosely received and wedged within the bore tapered portion. The mixingtip has at the inlet end a second mating assembly having opposedgenerally planar, arcuate first and second locking tabs of a commonpredetermined thickness slightly less than the distance between the riblocking faces of the first mating assembly and the neighboring shoulder.Each tab has at least one edge beveled at a common predetermined angle.The tabs are symmetrically disposed with respect to the cylindrical boreportion. The bore circumferential surface includes diametrically opposedfirst and second detent recesses and first and second ramps which arecontiguous at a proximal end, respectively, to the recesses.

[0021] Alternatively, a five section static mixing element is receivedand wedged within the bore tapered portion. It is believed that the useof a five section static mixing element will provide approximately 50%better mixing than the four section static mixing element. Those skilledin the art will appreciate that additional sections of the static mixingelement will provide further enhanced mixing and may therefore bedesirable.

[0022] According to the preferred embodiment of the present invention,each section of the static mixing element comprises a single turn screw.Each screw is clocked, i.e., configured so as to be right or lefthanded, opposite that of each adjacent screw and is oriented, withrespect to the leading and trailing edges thereof, at 90% with respectto each adjacent screw. Thus, as the two viscous materials flow from onescrew to the next screw, the viscous materials are split into twoportions, so as to effect desired mixing thereof. The screws aredisposed upon a common shaft. The screws taper in size such that theviscous materials flow through successively smaller screws as theviscous materials are dispensed.

[0023] The first and second mating assemblies are conjoined when theneck is inserted into the cylindrical bore portion in a relativeorientation such that each detent contacts a ramp distal end, therebydetermining an engaged configuration. The assemblies interlock when themixing tip is rotated in a first direction until each detent, traversingthe ramp and reaching the ramp proximal end, is received within arecess. Concurrently, each tab is closely received between one of thepluralities of rib locking faces and a shoulder. The mating assembliesare detachable when the mixing tip is rotated in the opposite directionuntil the neck and cylindrical bore portion are in the engagedconfiguration.

[0024] Optionally, a locking closure cap is utilized in place of themixing tip so as to better mitigate leakage during shipping. The lockingclosure cap attaches to the body in the same manner as the mixing tip.Preferably, the locking closure cap comprises a locking closure capliner formed of a comparatively resilient material which provides anenhanced seal between the locking closure cap and the body. The lockingclosure cap liner preferably comprises a groove formed therein andconfigured so as to receive a partition formed within the neck of thebody.

[0025] A more complete understanding of the present invention and otherobjects, aspects and advantages thereof will be gained from aconsideration of the following description of the preferred embodimentread in conjunction with the accompanying drawings provided herein.

DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is an exploded perspective view of a double-barreledsyringe according to the invention, including a double-plunger assembly,two pistons, a double-barrel assembly, a static mixing element, adetachable locking mixing tip, and alternatively, a detachable lockingcap;

[0027]FIG. 2 is a discharge end perspective view of the FIG. 1double-barrel assembly, including two shoulders, a neck with two outletpassages, and a mating assembly with two diametrically opposed detentsand two symmetrically disposed locking ribs for engaging andinterlocking with the mixing tip or cap;

[0028]FIG. 3 is an inlet end perspective view of the FIG. 1 mixing tip,including a mating assembly, having two locking tabs, which engages andinterlocks with the FIG. 2 mating assembly;

[0029]FIG. 4A is a combined exploded perspective and partial sectionalview of the FIGS. 2 and 3 mating assemblies before engagement;

[0030]FIG. 4B is a combined perspective and partial sectional view ofthe FIGS. 2 and 3 mating assemblies after engagement;

[0031]FIG. 4C is a combined perspective and partial sectional view ofthe FIGS. 2 and 3 mating assemblies after interlocking;

[0032]FIG. 5A is a perspective view of the FIGS. 2 and 3 matingassemblies before engagement;

[0033]FIG. 5B is a perspective view of the FIGS. 2 and 3 matingassemblies after engagement;

[0034]FIG. 5C is a perspective view of the FIGS. 2 and 3 matingassemblies after interlocking;

[0035]FIG. 6A is a transverse sectional view of the FIGS. 2 and 3 matingassemblies after engagement;

[0036]FIG. 6B is a transverse sectional view of the FIGS. 2 and 3 matingassemblies after interlocking;

[0037]FIG. 6C is a cross-sectional view of the FIG. 6B mating assembliestaken along offset line 6C-6C, showing each locking tab disposed withina recess determined by a FIG. 2 shoulder and locking rib;

[0038]FIG. 7 is a horizontal cross-sectional view of the FIG. 2discharge end and FIG. 3 inlet end when the mixing tip is locked to thedouble-barrel assembly;

[0039]FIG. 8 is a cross-sectional view orthogonal to FIG. 7;

[0040]FIG. 9 is a perspective view of a unitary double-barreled plungerhaving integrally formed seals at the distal ends thereof;

[0041]FIG. 10 is an enlarged side view of one of the distal ends of thedouble-barreled plunger of FIG. 9, showing the seal;

[0042]FIG. 11 is a cross sectional perspective view of the distal end ofthe plunger of FIG. 10;

[0043]FIG. 12 is a horizontal cross-sectional view of an alternativeconfiguration of the mixing tip, wherein a five element mixer is usedinstead of the four element mixer of FIGS. 7 and 8;

[0044]FIG. 13 is a cross-sectional view orthogonal to FIG. 12;

[0045]FIG. 14 is an enlarged side view of the five section mixingelement of FIGS. 12 and 13;

[0046]FIG. 15 is a perspective view of a locking closure cap showing thelocking closure cap liner thereof exploded therefrom;

[0047]FIG. 16 is an enlarged perspective view of the locking closure capof FIG. 15, showing the locking closure cap liner installed therein; and

[0048]FIG. 17 is a discharge end perspective view of the double-barrelassembly, including two shoulders, a neck with two outlet passagesseparated by a straight partition, and a mating assembly with twodiametrically opposed detents and two symmetrically disposed lockingribs for engaging and interlocking with the mixing tip or cap.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0049] While the present invention is open to various modifications andalternative constructions, the preferred embodiment shown in thedrawings will be described herein in detail. It is to be understood,however, there is no intention to limit the invention to the particularform disclosed. On the contrary, it is intended that the invention coverall modifications, equivalences and alternative constructions fallingwithin the spirit and scope of the invention as expressed in theappended claims.

[0050] The invention relates to an article of manufacture which isprimarily intended for storing and dispensing gels which are componentsof an admixture and which need to be kept separate until the admixtureis formed. However, the invention is not limited to particular types ofmaterial to be stored and dispensed, and can be used for storing anddispensing any material that can be placed within a syringe barrel andeffectively admixed by a static mixing tip.

[0051] Where used herein, the word “attached” means that the two partsreferred to (e.g., a locking rib and a shoulder or a plunger end-pieceand a piston) are either molded in a single piece, or are glued orforce-fitted together. However, other forms of attachment may besuitable, consistent with simplicity of manufacture and reliability ofoperation. Where used herein, the word “connected” means that the twoparts referred to (viz., the two mating assemblies) can be easilyseparated after being joined together in an interlocking combination.

[0052] Referring to FIGS. 1 and 2, a syringe body 10 includes adouble-barrel assembly 12 having juxtaposed first and second generallycylindrical barrels 14L, 14R having a common length and a generallycylindrical bore 16L, 16R, respectively, of a common diameterdetermining storage compartments 15L (not shown), 15R (not shown).Barrels 14L, 14R are bounded at a first (discharge) end 18L, 18R,respectively, by first and second shoulders 20L, 20R, respectively. Theshoulders have generally planar surfaces 21L, 21R, respectively, whichare coplanar and contiguous. A generally cylindrical neck 22 extendsfrom and is symmetrically disposed between the shoulders. As shown inFIG. 2, neck 22 includes first and second outlet passages 24L, 24R,divided by a partition 26. As best shown in FIG. 7, passages 24L, 24Rare in fluid communication, respectively, with barrels 14L, 14R. Barrels14L, 14R are open at an opposite (plunger) end 28L, 28R, respectively,which closely receives a piston 30L, 30R, respectively. Barrel ends 28L,28R are circumscribed by and rigidly attached to an arcuately-shapedfinger-grip 32.

[0053] The syringe body 10 further includes a double-plunger assembly 36having juxtaposed generally cylindrical first and second plungers 38L,38R of a common length. Each plunger extends at an end 40L, 40R proximalto a piston in an end-piece 42L, 42R rigidly attached to the piston 30L,30R, respectively. The plungers are attached at their distal end 44L,44R to a disc-shaped thumb-rest 46 so that when the thumb-rest isdepressed the plungers move forward in tandem, and the attached pistonsmove in tandem within the barrels.

[0054] Still referring to FIG. 2, syringe body 10 further includes afirst mating assembly 50 having diametrically opposed first and seconddetents 52, 54 extending outwardly from neck 22, and opposed first andsecond locking ribs 56L, 56R symmetrically disposed with respect to neck22. Ribs 56L, 56R each have a first (stand-off) portion 57L, 57R,respectively, generally parallel to the shoulders 20L, 20R,respectively, and generally orthogonal to a second (bracket) portion58L, 58R (not shown), respectively, rigidly attached, respectively, toshoulders 20L, 20R. Rib stand-off portions 57L, 57R each have twogenerally planar locking faces 59L, 60L, and 59R (not shown), 60R (notshown), respectively, which are generally parallel to and at a commondistance from the neighboring shoulder surface 21L, 21R, respectively,thus determining symmetrical recesses 62L, 62R (not shown),respectively. Preferably, double-barrel assembly 12, including neck 22,and mating assembly 50 are fabricated as a unit from a polymerizedalkene such as polypropylene by means of an injection molding process.

[0055] Referring to FIGS. 1 and 3, a generally conical mixing tip 70includes an inlet end 72 and a discharge end 74 and a bore 76therethrough. As best shown in FIG. 3, bore 76 has a generallycylindrical portion 78 proximate to inlet end 72 and extends in aconically tapered portion 80 (not shown) toward the discharge end 74.Cylindrical bore portion 78 is determined by a circumferential surface78S adapted to closely receive the neck 22. As best shown in FIGS. 7 and8, a static mixing element 82 is closely received and wedged within thetapered bore portion 80. The static mixing element 82 comprises a foursection static mixing element. That is, the mixing element 82 iscomprised of four separate single turn screws. Mixing element 82 isinserted in a random azimuthal orientation within bore portion 80 and sois not disposed in a predetermined orientation with respect to partition26 and outlet passages 24L, 24R when mixing tip 70 is attached todouble-barrel assembly 12. As further shown in FIGS. 7 and 8, when tip70 and assembly 12 are attached, proximate end 82P of mixing element 82and neck 22 are separated by a gap 83. Mixing tip 70 further includes anindented surface portion 84 to facilitate a person holding the tipbetween the thumb and fingers to rotate the tip.

[0056] Still referring to FIG. 3, the inlet end 72 of mixing tip 70includes a second mating assembly 90 having opposed generally planararcuately-shaped first and second locking tabs 92, 94 of a commonpredetermined thickness slightly less than the common width of recesses62L, 62R. Tabs 92, 94 are symmetrically disposed with respect tocylindrical bore portion 78 and have edges 93A (not shown), 93B (notshown) and 95A, 95B, respectively, which are each beveled at an angle ofabout 8 degrees. Tabs 92, 94 are rigidly attached, respectively, tostructural ribs 98, 100 disposed symmetrically with respect to boreportion 78, and extending in generally oval-shaped collar portions 102,104, respectively. The two collar portions partially circumscribe inletend 72 and extend so that tab 92 is rigidly attached at an interior edge92E (not shown) to collar portion 104, and tab 94 is rigidly attached atan interior edge 94E to collar portion 102. Surface 78S includesdiametrically opposed first and second detent recesses 110, 112 and aplurality of corrugations 114. As shown in FIGS. 4A, 4B, 6A and 6B,recesses 110, 112 are each contiguous to first and second ramps 116,118, respectively, which are generally planar sloping portions of thesurface 78S. As shown in FIGS. 4B and 6A, when neck 22 is insertedwithin bore portion 78, each detent 52, 54 contacts a ramp 116, 118,respectively, at a ramp end 120, 122, respectively, distal to recess110, 112, respectively. As shown in FIGS. 4C and 6B, when mixing tip 70is rotated counterclockwise with respect to double-barrel assembly 12,each detent 52, 54 traverses the contacting ramp to the proximal rampend 124, 126, and is received within the recess. Preferably, mixing tip70 and associated mating assembly 90 are fabricated as a unit from apolymerized alkene such as polypropylene by means of an injectionmolding process. As shown in FIG. 1, mixing tip 70 may be replaced by aclosure cap 130 having a mating assembly identical to mating assembly 90so that cap 130 is interchangeable with mixing tip 70.

[0057]FIGS. 4A and 5A show the proper relative orientation betweenmating assemblies 50 and 90 so that neck 22 can be inserted into boreportion 78. FIGS. 4B and 6A show the mating assemblies engaged but notyet interlocked. FIG. 5B shows the disposition in the engaged positionof collar portion 102 with respect to locking ribs 56L, 56R of matingassembly 50. In FIGS. 4B and 6A, arrows 120, 121 show the(counterclockwise) rotational direction for interlocking. FIGS. 4A and4B show rib stand-off portions 57L and 57R with respective locking faces59L, 60L and 59R, 60R. FIGS. 4B and 6A further show the respectivedisposition of locking tabs 92, 94 of mating assembly 90 and ribstand-off portions 57L, 57R of mating assembly 50 before interlocking.FIGS. 4C and 6B show the respective disposition of locking tabs 92, 94and rib stand-off portions 57L, 57R after interlocking when tabs 92, 94have been closely received within recesses 62L, 62R, respectively, anddetents 52, 54 received within recesses 110, 112, respectively. Tabinsertion and removal are facilitate by beveled edges 93A, 93B of tab 92and beveled edges 95A, 95B of tab 94. FIG. 5C shows the disposition inthe interlocked position of collar portion 102 with respect to lockingribs 56L, 56R.

[0058]FIGS. 6 and 7 show locking tabs 92, 94 received within recesses62L 62R, respectively, determined, respectively, by shoulders 20L, 20Rand rib stand-off portions 57L, 57R with locking faces 59L, 60L and 59R,60R. As best shown in FIG. 7, locking tabs 92, 94, when received withinrecesses 62L, 62R, contact locking faces 59L, 60L and 59R, 60R,respectively. FIG. 8 shows detents 52, 54 in relation, respectively, torecesses 110, 112 and to collar portions 102, 104.

[0059] After dispensing a desired amount of admixture, a user typicallywould detach the mixing tip 70 from the double-barrel assembly 12 byrotating the tip clockwise until detents 52, 54 reach ramp distal ends120, 122, at which position locking tabs 92, 94 are disengaged fromrecesses 62L, 62R, and then pulling apart the mixing tip anddouble-barrel assembly. The corrugation in surface 78S contiguous toeach ramp distal end acts as a stop for the detent, thus preventingover-rotation and ensuring that mating assemblies 50 and 90 return tothe engaged position. The closure cap 130 may then be connected to thesyringe body 10 by using the same engagement and locking procedure asused for the tip.

[0060] Preferably, the double-barrel assembly 12 and attached matingassembly 50, double-plunger assembly 36, mixing tip 70 and attachedmating assembly 90, and closure cap 130 are fabricated from apolymerized alkene such as polypropylene. Preferably, the length betweenthumb-rest 46 and discharge end 74 of mixing tip 70 is about 6.75 incheswhen plungers 38L, 38R are fully retracted. Preferably, the combinedwidth of juxtaposed barrels 14L, 14R is about 0.65 inch.

[0061] Referring now to FIGS. 9-11, the plunger alternatively comprisesa unitary construction double-barreled plunger 336 having sealing tips200L and 200R formed integrally with shafts 210L and 210R of theplungers 338L and 338R thereof. In this manner, the need for separatesealing tips, such as those of pistons 30L and 30R of FIG. 1, iseliminated. By eliminating such separate sealing tips, both thematerials and assembly costs associated with the plunger assembly 336are reduced.

[0062] With particular reference to FIGS. 10 and 11, the right sealingtip 200R comprises a shaft 210R having a first neck 212 attaching theshaft to 210R to an alignment ring 204 and a second neck 208 attachingthe alignment ring 204 to a seal 202R. Although only the distal end ofone plunger 338R is shown in FIGS. 10 and 11, it will be appreciatedthat both plungers 338L and 338R are substantially identical.

[0063] The shaft 21 OR has a diameter, Dimension A, which issubstantially greater than a diameter, Dimension B, of the first neck212. The diameter of the shaft 21 OR, Dimension A, is somewhat less thanthe diameter of the cylindrical bore 16R (FIG. 1) within which the shaft210R is disposed, so as to facilitate easy movement of the shaft 210Rwithin the cylindrical bore 16R. The alignment ring 204 comprises afirst portion 214 having a diameter, Dimension C, which is approximatelyequal to the diameter, Dimension A, of the shaft 210R. The alignmentring 204 also has a second portion 216 which has a diameter, DimensionD, which is greater than the diameter, Dimension C, of the first portion204 thereof. The diameter, Dimension D, of the second portion 216 of thealignment ring 204 is approximately equal to the diameter of thecylindrical bore 16R within which the plunger 338R is slidably disposed,so as to provide a close fit therewith. The second portion 216preferably defines a radiused or rounded surface where it contacts thecylindrical bore 16R.

[0064] Second neck 208 has a diameter, Dimension E, which is less thanthe diameter, Dimension C, of the first portion 214 of the alignmentring 204 and which is greater than the diameter, Dimension B, of thefirst neck 212.

[0065] The seal 202R has a first portion 220 which has a diameter,Dimension F, which is approximately equal to the diameter, Dimension D,of the second portion 216 of the alignment ring 204 (and which is thusapproximately equal to the diameter of the cylindrical bore 16R). Theseal 202R also has a second portion 206 which has a diameter, DimensionG, which is substantially greater than the diameter, Dimension F, of thefirst section 220 of the seal 202R. The second section 206 of the seal202R is defined by a flare which is comprised of a relatively thin, andconsequently comparatively flexible, portion of the seal 202R, and whichtherefore conforms generally in diameter to the cylindrical bore 16R. Inthis manner, the second portion 206 of the seal 202R provides a sealbetween the plunger 38Y and the first bore 16R within which the plunger338R is disposed.

[0066] The alignment ring 204 functions so as to maintain desiredalignment of the seal 202R with respect to the cylindrical bore 16R,particularly during use, e.g., dispensing of fluid, of the syringe.During use of the double-barreled syringe, the shaft 210R tends to flexor bow as the thumb rest 46 is pushed so as to force viscous materialfrom the cylindrical bore 16R. The alignment ring 204 mitigatesmisalignment of the seal 202R and consequent undesirable leakage ofviscous material thereby. The alignment ring 204, in combination withthe neck 208 and the seal 202R, define a spool-like member which issubstantially more resistant to misalignment within the cylindrical bore16L than is the seal 202R alone.

[0067] The first neck 212, which has a substantially smaller diameter,Dimension B, than the diameter, Dimension E, of the second neck 208,permits some desired movement of the shaft 210R of the plunger 338R,with respect to the combination of the alignment ring 204 and the seal202R (which are rigidly attached to one another) such that bending ofthe shaft 210R does not effect substantial misalignment of the seal202R.

[0068] The diameter, Dimension C, of the first section 214 of thealignment ring 204 is substantially less than the diameter of thecylindrical bore 16R, and the second section 216 of the alignment ring204 has a diameter, Dimension D, approximately equal to that of thediameter of the cylindrical bore 16R, so as to provide a desired amountof friction between the alignment ring 204 and the cylindrical bore 16R.The radiused or rounded contact surface of the second section 216 alsocontributes to providing the desired amount of friction between thealignment ring 204 and the cylindrical bore 16R. According to thepreferred embodiment of the present invention, Dimension A isapproximately 0.241 inch, Dimension B is approximately 0.129 inch,Dimension C is approximately 0.238 inch, Dimension D is approximately0.250 inch, Dimension E is approximately 0.165, Dimension F isapproximately 0.250 inch and Dimension G. is approximately 0.260 inch.The unitary construction double-barreled plunger 336 is preferablyfabricated from a polymerized alkene such as polypropylene.

[0069] Referring now to FIGS. 12-14, the mixing tip 70A alternativelycomprises a five section static mixing element 82A. The five sectionstatic mixing element 82A comprises first 240A, second 240B, third 240C,fourth 240D and fifth 240E sections. Each section 240A-240E of thestatic mixing element 82A preferably comprises a single turn screwformed upon a common shaft 242 (best shown in FIG. 14) such that eachsection has a different clock sense, i.e., rotates in a differentdirection, from each adjacent section. That is, if the screw of a givensection 240A-240E is clockwise, then any immediately adjacent section(s)will have a counter clockwise sense. Further, the leading edge of eachscrew is oriented at approximately 90 degrees with respect to thetrailing edge of each preceding screw, such that as fluid flows from onescrew to another, the fluid is cut approximately in half, so as toeffect desired mixing thereof. The five section static mixing element82A is preferably fabricated from a polymerized alkene such aspolypropylene.

[0070] Referring now to FIGS. 15 and 16, a locking closure cap 130preferably comprises a locking closure cap liner 260 for enhancing theseal between the locking closure cap 130 and the neck 22 so as toprevent undesirable leakage of fluids from the first 14L and second 14Rcylindrical barrels.

[0071] According to the preferred embodiment of the present invention,the locking closure cap liner 260 comprises a base 262 and two outwardlyextending protrusions 264 and 266 which define a groove 268therebetween. The groove 268 is configured so as to receive a generallyplanar partition 26A of the neck 22, as shown in FIG. 17. The twoprotrusions fit tightly within the two outlet passages 24L and 24R so asto effect desired sealing thereof. The base 262 provides further sealingas it is compressed against the neck 22 by the locking closure cap 130.The base 262 of the locking closure cap 130 is preferably compressed byapproximately 0.008 inch when the locking closure cap 130 is attached tothe syringe body 10.

[0072] The locking closure liner is preferably fabricated frompolyolefin elastomer, preferably ENGAGE 8401 (ENGAGE is a federallyregistered trademark of Dupont Dow Elastomers). The locking closure capis preferably fabricated form a polymerized alkene, such aspolypropylene.

[0073] The locking closure cap liner 260 is preferably installed withinthe locking closure cap by inserting the two outwardly extendingprotrusions 264 and 266 into the neck 22 such that the partition 26A isreceived within the locking closure cap liner 260. Then, the lockingclosure cap 130 is attached to the syringe body 10 in the same mannerthat the mixing tip 70 is attached thereto. The partition 26A preventsrotation of the locking closure cap liner 260 as the locking closure cap130 is rotated into the individual position thereof.

[0074] All of the polypropylene components of the present invention arepreferably comprised of Polymerland 3320 AP polypropylene.

[0075] It is understood that the exemplary double-barreled syringedescribed herein and shown in the drawings represents only a presentlypreferred embodiment of the invention. Indeed, various modifications andadditions may be made to such embodiment without departing from thespirit and scope of the invention. For example, the unitary constructionplunger may alternatively comprise a plurality of alignment rings.Further, various different configurations of the locking closure capliner are contemplated. Further, various numbers and configurations ofthe individual sections of the static mixing element are contemplated.

[0076] Thus, these and other modifications and additions may be obviousto those skilled in the art and may be implemented to adapt the presentinvention for use in a variety of different applications.

What is claimed is:
 1. A syringe for dispensing two viscous materials asan admixture, comprising: an integrally molded housing having a firstand a second barrel that are symmetrical and fixedly opposed along acenter line, the barrels are bounded at a discharge end, have agenerally cylindrical neck extending from and symmetrically disposed atthe discharge end along the center line, the neck including first andsecond outlet passages in fluid communication, respectively, with thefirst and second barrels, an exterior circumferential surface definingthe shape of the barrels, and a gripping member disposed at a proximalend of the housing; a first mating assembly having opposed first andsecond locking ribs symmetrically disposed with respect to said neck andrigidly attached to the bounded discharge end, the first and secondlocking ribs having at least a portion aligning with the exteriorcircumferential surface of the two barrels, and wherein the first matingassembly is configured to receive a mixing tip or a locking closure cap;wherein the mixing tip has an inlet, an outlet, a generally cylindricalbore defined by a circumferential surface adapted to closely receivesaid neck, and a second mating assembly having opposed generally planarfirst and second locking tabs symmetrically disposed with respect to thebore, the two mating assemblies conjoining when the neck is insertedinto the mixing tip bore in a relative orientation, and wherein the twomating assemblies interlock when the mixing tip rotates in a firstdirection and the locking tabs slide under the first and the secondlocking ribs until a stop is achieved, the two mating assemblies aredetachable when the mixing tip is rotated in an opposite direction; andwherein the mixing tip further including a static mixing element havinga plurality of intertwined sections disposed within the cylindrical borefor mixing the two viscous materials as the two viscous materials aredispensed from the first and the second barrels.
 2. The syringe of claim1, wherein the intertwined sections comprise a plurality of single turnscrews, each screw rotating in a direction opposite that of an adjacentscrew and oriented at 90 degrees with respect thereto such that as thetwo viscous materials flow from one screw to the next screw the viscousmaterials are split into two portions to effect mixing thereof.
 3. Thesyringe of claim 2, wherein the screws are disposed upon a common shaft.4. The syringe of claim 2, wherein the screws taper in size such thatthe viscous materials flow through successively smaller screws as theviscous materials are dispensed.
 5. The syringe of claim 1, furthercomprising a unitary construction double-plunger having juxtaposed firstand second plungers of a common length, each plunger being configured tobe received by each of the two barrels.
 6. The syringe of claim 1,further comprising a unitary construction double-plunger havingjuxtaposed first and second plungers of a common length, each plungerhaving an alignment ring formed proximate a distal end thereof and aseal formed distal of the alignment ring, each alignment ring enhancingalignment of a seal with respect to the one of the barrels.
 7. Thesyringe of claim 1, further comprising a unitary constructiondouble-plunger having juxtaposed first and second plungers, each plungerhaving a shaft, an alignment ring formed at a distal end of the shaftand a seal formed distally of the alignment ring, the alignment ringcoupled comparatively flexibly to the shaft of the plunger and thealignment ring coupled comparatively rigidly to the seal.
 8. The syringeof claim 1, further comprising a unitary construction double-plungerhaving juxtaposed first and second plungers, each plunger having ashaft, an alignment ring formed at a distal end of the shaft and a sealformed distally of the alignment ring, the alignment ring attached tothe shaft by a first neck and the seal attached to the alignment ring bya second neck, the first neck having a smaller diameter than the secondneck to facilitate movement of the alignment ring and the seal relativeto the shaft.
 9. The syringe of claim 1, further comprising a lockingclosure cap having a generally cylindrical bore sized to receive saidneck, a second mating assembly having opposed generally planar first andsecond locking tabs symmetrically disposed with respect to said bore,said surface having opposed first and second detent recesses and firstand second ramps contiguous at a proximal end, respectively, to saidrecesses, the mating assemblies conjoining when the neck is insertedinto the bore in a relative orientation such that each detent contacts aramp distal end, thereby determining an engaged configuration, themating assemblies interlocking when the locking closure cap is rotatedin a first direction until each detent, traversing the ramp and reachingthe ramp proximal end, is received within a recess, and each tab isclosely received between one of said pluralities of rib locking facesand a shoulder, the mating assemblies detachable when the lockingclosure cap is rotated in the opposite direction until the neck and boreare in said engaged configuration, and a locking closure cap linercomprised of a resilient polymer material disposed within the lockingclosure cap and configured to engage and seal the neck to mitigateleakage of the two viscous materials from the first and second barrels.10. The syringe of claim 9, wherein the neck comprises a partition andthe locking closure cap liner comprises a groove configured to receivethe partition.
 11. A syringe for mixing and administering a first and asecond content, the syringe comprising: an integrally molded bodyportion with two symmetrical barrels having external circumferentialsurfaces contiguously attached along a center contact line, each barrelhaving distal and proximal ends; the distal end of each barrel is closedand has an attached locking rib for gripping a mixer, the locking ribseach comprising a first portion which aligns with the externalcircumferential surface of the corresponding barrel and a second portionwhich is generally perpendicular to the first portion and which has aface, said proximal end of the barrels includes a gripping member forimproved gripping and an inlet for receiving a plunger; an outlet neckat the closed distal end symmetrically disposed along the center contactline and equally spaced between the locking ribs; wherein said outletneck is in fluid communication with the two barrels; wherein the mixerincludes an inlet, an outlet, and a bore defined by a circumferentialsurface adapted to closely receive the outlet neck; the mixer furtherincluding a mating assembly which comprises a pair of abutting wallmembers and a pair of locking tabs, wherein the abutting wall membersare configured to abut against the face on the second portion of each ofthe locking ribs for stopping a relative orientation between the mixerand the outlet neck, and wherein the locking tabs are configured tofrictionally engage an underside of the second portion of the lockingrib; and wherein the mixer further includes a series of intertwinedscrews in frictional engagement with the bore.
 12. The syringe of claim11, wherein the static mixing element comprises a plurality of singleturn screws, each screw rotating in a direction opposite that of anadjacent screw and oriented at 90 degrees with respect thereto, suchthat as the two viscous materials flow from one screw to the next screwthe viscous materials are split into two portions to effect mixingthereof.
 13. The syringe of claim 12, wherein the screws are disposedupon a common shaft.
 14. The syringe of claim 12, wherein the screwstaper in size such that the viscous materials flow through successivelysmaller screws as the viscous materials are dispensed.
 15. The syringeof claim 11, further comprising a unitary construction double-plungerhaving juxtaposed first and second plungers of a common length, eachplunger being configured to be received by each of the two barrels.